1. Technical Field
Various embodiments relate to a semiconductor integrated device, and more particularly, to a semiconductor memory device and an I/O control circuit.
2. Related Art
A semiconductor memory device can typically be placed in one of a number of different input/output (I/O) option modes, where each I/O option mode supports an associated data I/O bandwidth. The data I/O bandwidth defines the amount of data that can be inputted in response to a write command and/or outputted in response to a read command. Examples of I/O option modes may include a X4 I/O option mode, a X8 I/O option mode, and a X16 I/O option mode.
When the semiconductor memory device is placed in a specific I/O option mode, one or more different control functions that are associated with that I/O option mode are enabled. Examples of such control functions include, but are not limited to, a data masking control function (WDM), a data bus inversion control function (DBI), and a termination data strobe control function (TDQS). There are two types of DBI control functions: a write DBI control function (WDBI) function and a read DBI control function (RDBI).
In some cases, when a semiconductor memory device operates in a particular I/O option mode, a control function that is not associated with that I/O option mode may be inadvertently enabled in error.